摘要
该文针对极弱电网、严重故障场景研究传统故障穿越策略对虚拟同步发电机(virtual synchronous generator,VSG)型构网变流器大干扰稳定性的影响。首先,通过理论推导并建立传统故障穿越策略下VSG构网特性表征模型,用以表征电网故障阶段VSG构网同步特性与电压支撑特性;在此基础上,结合故障成功穿越所需具备的条件,进一步提出故障穿越可行域的概念以及故障严重程度的界定原则,明确传统VSG故障穿越策略对于不同程度故障、不同限流幅值的适用范围;并且,针对传统故障穿越无法覆盖全故障场景的问题,提出一种名为动态限幅电压控制的新型控制方式(dynamic limiting voltage control,DLVC),并在其基础上进一步提出一种增强型VSG故障穿越策略(dynamic limiting voltage control fault ride through,DLVC-FRT),其具有近区无功、远区电压控制的灵活控制特性,在限制短路电流的同时可有效提升VSG在极弱电网场景下对电网电压的支撑能力;最后,在PSCAD/EMTDC中构建仿真,并验证所提策略的有效性。
This paper studies the influence of conventional fault ride through strategy on the stability of VSG large disturbance under extremely weak grid and severe grid voltage dip condition.First,the grid-forming characteristic characterization model of VSG under conventional fault ride through strategy is derived theoretically.On this basis,the concept of fault ride through feasible region is further proposed in considering the conditions required for successful fault ride through.The feasible region defines the application range of the conventional VSG fault ride through strategy in the case of different severity level faults.In addition,to solve the problem that conventional strategy cannot ride through different severity level faults successfully,this paper proposes an enhanced VSG fault ride through strategy based on dynamic current-limiting voltage control unit.With the flexibility of near-area reactive power and far-area voltage control,VSG can effectively improve its support ability to grid voltage while limiting short-circuit current effectively under extremely weak grid condition.Finally,simulation is constructed in PSCAD/EMTDC,and the effectiveness of the proposed control strategy is verified.
作者
裴建楠
赵冬梅
白俊辉
刘崇茹
PEI Jiannan;ZHAO Dongmei;BAI Junhui;LIU Chongru(School of Electrical and Electronic Engineering,North China Electric Power University,Changping District,Beijing 102206,China)
出处
《中国电机工程学报》
北大核心
2025年第23期9362-9375,I0024,共15页
PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING
基金
国家重点研发计划项目(2022YFB2402700)
国家电网有限公司科技项目(52272222001J)。
关键词
构网技术
虚拟同步机
故障穿越
极弱电网
大扰动稳定性
grid-forming technology
virtual synchronous generator(VSG)
fault ride through
extremely weak grid
large disturbance stability
